[YMTC]: Inspect Redabot's Pneumatics

[Richard Wallace]

Redabot has two 3/4" bore x 1" stroke pneumatic cylinders that are used to shift gears, and no other pneumatic actuators. Frequent gear shifts are not required, so the air needed can be stored in Clippard tanks, which team Redabot fills to 120 psi before each match. Redabot does not have an on-board compressor, but does have (1) a 0-160 psi pressure gauge attached to one of the Clippard tanks, (2) a correctly installed Norgren regulator set to provide 60 psi air to the valve that drives the gearshift cylinders, and (3) a correctly installed relief valve, with a fitting attached for connecting the off-board fill tube.

To comply with robot rules <R95> and <R96> which require the Thomas compressor to be used for storing air in the Clippard tanks even if the compressor is not on-board the robot, Team Redabot has cleverly constructed a portable compressor kit including an EX18-12 battery, a 20A in-line fuse, a Spike relay, and a custom circuit with a mechanical switch to enable the Spike.

Team Redabot uses the following procedure to fill Redabot's Clippard tanks before each match: (1) open the relief valve and connect the fill tube from their portable compressor kit, (2) switch on the compressor, (3) read the on-board Clippard tank pressure gauge and switch the compressor off when it reaches 120 psi, (4) close the relief valve, (5) disconnect the fill tube.

Today is Thursday. Team Redabot has passed all of the 2006 FRC Robot Inspection Check List (http://www2.usfirst.org/2006comp/other/2006_Robot_Inspection_Checklist-rev_F.pdf) items except the pneumatics area. You, as their robot inspector at the 2006 Championship, have just witnessed a demonstration of the tank filling procedure described above, and it worked perfectly.

Does Redabot pass inspection? Why, or why not?

Cite any robot rules, Team Updates, and/or GDC Q&A responses that support to your decision.

[Silent_Stryker]

one possible thing i can see right now is rule R97

<R97>
The Nason Co. pressure switch must be attached to the compressor output or Clippard tank(s) and be wired to the digital I/O port on the RC. The pressure switch CANNOT be used to directly power the compressor.

another is that the rules specify a 20A circuit breaker for the off-robot compressor, while this specifies that redabot is using a 20A fuse. whether or not that is a distinguishable difference there, i have no idea.

[Imajie]

From Inspection Sheet:
If the robot design uses an “off-robot” air compressor, the team must use the KOP Thomas compressor with a 20A circuit breaker and a Spike Relay Module. The Spike must be controlled with the Robot Controller and the Robot Controller must sense the Nason Co. pressure switch.
R02, R90, R97
Since the compressor is powered by manually activated spike, it is illegal.

[dlavery]

To provide even more information:

Redabot's set-up is illegal. It is a violation of Rule <R97>.
<R97> The Nason pressure swtich must be connected to the output end of one of the Clippard tanks to sense the tank's pressure. The two wires from the pressure switch must be conneted directly to a digital input and ground terminal on the Robot Controller, and the controller must be programmed to sense the state of the switch and operate the spike relay that powers the compressor. The Parker Pressure Vent valve must be connected to a Clippard tank such that, when manually operated, it will vent to the atmosphere to relieve any stored pressure. The valve must be placed on the robot so that it is visible and accessible.
Since the RC is not controlling the compressor, utilizing the input from the pressure switch, Redabot is in violation. It is also a violation of this question (http://forums.usfirst.org/showthread.php?t=793) from the Q&A system. QED.

-dave

[Steve W]

There is also no mention of the 60 psi guage downline of the regulator to show the proper working pressure of 60psi.

[Richard Wallace]

There is also no mention of the 60 psi guage downline of the regulator to show the proper working pressure of 60psi.Good catch, Steve.

I was thinking that the Norgren primary regulator (K47) is often close-coupled to the Norgren 0-160 psi gauge (K410), but that is not always true. So I should have mentioned the gauge along with the regulator. Both the storage pressure (<120 psi) and the working pressure (<60 psi) must be indicated by gauges on the robot.

[ttedrow]

I did not find anything new. But how did team reabot make it the the championship with this setup. It would not have passed at my regional.

[dlavery]

I did not find anything new. But how did team reabot make it the the championship with this setup. It would not have passed at my regional.

Was your inspection based on the 2006 rules or the 2007 version?

Check the date of the original question. :)

-dave